I think that the intended audience of the blog are those who might be unaware or skeptical of the "Occupy" movement. The tone in which he initially demonstrates towards the movement and what he shows at the end is intended to bring understanding on behalf of the outsider who is not fully sold on the goals and purposes of the movement. The audience he writes for are these individuals, ones who might lack the understanding of the movement. The opening paragraph of the blog helps to establish this as Stuchbery talks about his initial view of the movement as one where transcendent ideas will never be realized:
Sure, that’ll be no sweat’, I sneered, ‘then they;ll establish world peace and develop limitless energy’.
Yet, this cynicism is replaced by an authentic sense of hope and progressivism as the blog continues. This is meant to appeal to those who exist on the outside of the movement. I don't think that that his audience are those directly involved in the movement precisely because they already know the movement's ends. The fact that Stuchbery talks about how the movement was organized, inclusive of all, providing food and child care, and represented something different than its stereotype indicates that the intended audience are those who might not understand or be familiar with the movement.
Consider the closing of the article as evidence of this idea that getting people to care and to participate in passionate debate about the issue of our times is the fundamental driving force of the movement and the end lesson that Stuchbery takes from it:
Around six, I decided to leave. I left the protest and walked down Swanston Street, amidst a cloud of staggering punters on their way home from the races. At one point I walked beside a conservatively-dressed older woman, and her husband. Turning to the gathering she stopped, frowned and paused for a second before sneering ‘Look at that rabble. Who... cares?’.
I think that’s the point, lady.
The idea of getting people to "care" is what drives the movement and is also what Stuchbery gets from his experience. In this, it is evident that he wishes to include more people who might not be actively involved in the movement or even possess a biased view against it. In this, the mere idea of "caring," Stuchbery is trying to increase the reach of the movement by suggesting that he used to believe one thing about it and now believes another, a transformation that he believes is possible for more people if they are receptive to the movement's message.